Method of applying high pressure to a body



y 1961 E. BARBERA 2,990,583

METHOD OF APPLYING HIGH PRESSURE TO A BODY Filed May 19, 1959 L '4 laINVENTOR.

EDMUND BARBERA ATTORNEY Unikdsw F rm 2,990,583 METHOD 'OF APPLYING HIGHPRESSURE.

. a TO A BODY Edmund Barbera,'15938 95th St., Howard Beach, N.Y. FiledMay 19, 1959, Ser. No. 814,185 6-Claims. (Cl. 18-593) This inventionrelates to a method of applying high pressures to a body, and moreparticularly concerns a method of applying high pressures to variousforms of solid matter to effect a change of state or form therein.

It has been proposed to exert high pressures on confined bodies byvarious means including hydraulic rams and the like; such proceduresusuallybeing accompanied by the application of heat at elevatedtemperatures. However, the apparatus involved is complex, particularlyin respect to the hydraulic pressure portion thereof, and entailsexpensive installations.

Accordingly, an object of this invention is to provide an improvedmethod of applying high pressures to a confined body, which involvesrelatively simple and inexpensive apparatus.

A further object of this invention is to provide an improved method ofthe character described which achieves very substantial unit pressuresfor application to powders, sheet and other forms of solid material in aconfined state. 7

Another object of this invention is to provide an improved, economicalprocedure for transforming amorphous carbon to a crystalline form havinga hardness substantially equal to that of the diamond.

Still another object of this invention is to provide an improvedprocedure for rapidly and simply converting metals into refractorycarbides.

Yet another object of this invention is to provide an improved procedurefor applying high pressures to forming dies whereby various solidmaterials in sheet or other form, may have their original shape variedto suit a par ticular purpose.

Other objects of this invention will in part be obvious and in parthereinafter pointed out.

In the drawing, the figure is a longitudinal sectional view of a deviceuseful in practicing the process of the instant invention.

It has been found that freezable, expansible liquid, such as water orthe like, may be used in association with a body of. material, in anelongated chamber which confines both liquid and body, to exert veryhigh unit pressures on the body, upon subjecting the chamber totemperatures which will freeze and expand the liquid. Thus, there may beachieved a change of state or form in the body of the material soenclosed. It has been found that carbon in amorphous form, such asfurnace black, graphite and the like, may be readily converted into acrystalline form having a hardness of about 9.8

Also, refractory metal such as titanium, tungsten, boron and the like,may be admixed with carbon and converted into their respective carbides.Furthermore, forming dies may be arranged to have transmitted thereto,very high pressures in a unique manner, whereby such dies may be used tovary the shape or form of various solid materials in sheet or otherphysical form.

The process in accordance with the instant invention is suitably carriedout in an enclosed chamber, such as shown in the figure. Thus, suchchamber may take the form of a tubular member 10 formed of hard alloysteel and having a longitudinal bore 11 which is closed at the end 12 bya wall of substantial thickness. The bore 11 at the upper end of saidmember, includes a slightly enlarged bore portion 13 providing anannular shoulder 14,

for the purpose hereinafter appearing.

A piston 15 is disposed in bore portion 13, seating on shoulder 14. Thepiston 15 includes at its upper end a ram portion 16. Acap 17 also ofsuitably formed alloy steel is removably secured to the open end oftubular member 10'to close the same, by bolts 18. Inter-posed betweenthe upper end of member 10 and cap 17 'is a clearance ring 19 having anopening which will pass the piston 15.

An asbestos ring-20 is seated on clearance ring 19 and its centralopening will pass ram portion 16 of piston 15. A charge ring 21 isdisposed between cap 17 and asbestos ring 20. Charge ring 21 has acentral charge chamber 22, together with electrical resistance elements23 surrounding chamber 22 for raising the temperature thereof. Thecharge chamber 22 has a diameter substantially equal to the diameter ofram portion 16 of piston 15.

The piston 15 is adapted to be moved by substantial pressures generatedin bore 11 in order to exert very high unit pressures on the contents ofcharge chamber 22 by way of ram 16 as the same enters charge chamber 22.

To this end, a tubular envelope 24 closed at the lower end and open atits upper end 25 is adapted to be filled with water or other freezable,expansible liquid. The envelope 24, which if formed of thin flexiblemetal, is adapted to be located in the bore 11 of tubular member 10 inan upright position thereof, the walls of said bore having beenpreviously coated with a thin layer of silicone grease or other lowtemperature type of lubricant.

An additional quantity of water or other expansible liquid is added tothe bore 11 to bring the level thereof up to shoulder 14. The piston 15is then seated on shoulder 14 within bore portion 13. The clearance ring19, the asbestos ring 20, the charge ring 21 and cap 17 are thereafterassembled in place on member 10 and retained therein by bolts 18. It isunderstood that charge ring 21 has the chamber 22 thereof filled withthe specific material which is to be treated.

The process involved includes the initial step of applying freezingtemperatures to a zone of the tubular member 10 indicated at 26, therebyfreezing a portion of the liquid in bore 11 which is immediately belowpiston 15. This may be readily accomplished by wrapping freezing coils,not shown, about zone 26. Such frozen slug of liquid forms a sealbetween piston 15 and the remainder of the freezable liquid withinenvelope 24. The entire tubular member 10 is now inverted andprogressively inserted into a suitable freezing bath whereby thecontents of envelope 24 are progressively frozen. Such freezing bath maycomprise any of the well known freezing media including methylenechloride, frozen carbon dioxide admixed with isopropyl alcohol oracetone, liquid carbon dioxide or the like.

It will be apparent that the freezable expansible liquid within envelope24 as it is progressively frozen will expand longitudinally to exertvery substantial pressures against piston 15. The resultant pressuresare effective to move piston 15 and its ram portion 16 into the chargechamber 22 of charge ring 21, thereby exerting very high pressure on thecontents of said chamber. If desired, the heating elements 23 may beenergized by a current, through electrical connections not shown, toincrease the temperature of the contents of chamber 22, to selectedvalues concomitantly with the application of pressure. It has been foundthat with the very high pressures available in the apparatus disclosedherein, the contents of chamber 22 may be quickly and readily convertedinto various forms in accordance with the nature of the original charge.Thus, it has been found that upon filling chamber 22 with carbon black,lampblack or other suitable form of amorphous carbon, there is produceda shiny, crystalline body which has upon test, a hardness of 9.8+.

Alternatively, charges have been prepared for chamber 22, which consistof an admixture of carbon and refractory metals such as tungsten,titanium, boron or the like in stoichiometric proportions. In suchcases, the resultant chargeupombeing .subjectedto the pressuresdeveloped withintubular member 110, have been converted-to therespective refractory carbides.

-It'has been found that upon varying the length of the tubular member.10 and thereby varying the extent of the column of freezable liquidcontained within bore 11, the ultimate :pressures developed ,and appliedto piston 15 may be adjusted to desired values.

It is further understood that the charge ring 21 may the configurationof chamber 22 varied so as to accommodate other solid materials whichare to be altered as to shape or form. Accordingly, the piston 15 willhave its ram portion 16 modified as to configuration so as to becomplementary to the chamber'22 ,in charge ring 21. Thus dies ,may beused for varying the shape and form of metals and the like.

Envelope '24 provides a convenient means for holding the liquid which isto be frozen while the same is in bore 11 of member 10. However, theenvelope 24 may be omitted, in which case, the .water is directly placedwithin said bore 11. The lubricanton the walls of bore 11 preventsadhesion of the freezing liquid to the walls of bore 11. The asbestosring '20 tends to insulate the charge ring 21 from the body of tubularmember 10, and is particularly effective when heatingelements 23 areenergized to raise the temperature of vthe charge in chamber 22 whilepressure is being applied by piston 15.

It has been found that the initial formation of the frozen seal at ,zone26 in bore .11 is highly effective in preventing leakage of liquid topiston 15 during thefreezing operation. Despite the pressures developed,such seal shows no cold flow, thereby allowing for optimum operation .ofthe piston 15.

In order .to achieve any desired pressure, adjustments may be made byvarying the extent in reduction of temperature of the freezable,expansible liquid in bore 11. It is understood that with an increase inresistance offered by the charge in chamber 22, .the temperature atwhich the liquid freezes, is lowered. In addition, the length of thebore 11 may be varied to adjust the extent of linear expansion of .theliquid .as the same freezes.

By varying the temperature of the freezing medium to which the device issubjected, or by changing the length of the bore 10; or by a combinationthereof, desired pressures may be attained. Thus, the pressures achievedbear a substantially inverse relation to the freezing temperaturesapplicable to device 10.

Once the temperature of the liquid within bore "11 has been lowered to adesired value by the freezing :bath or other freezing medium used, theeifect of the developed high pressures on the contents of chamber 22 isalmost instantaneous. The device 10 may then be readily disassembled, byremoving cap 17 therefrom; to allow recovery of the converted ormodified charge in chamber 22.

As various changes might be made in the embodiments of the inventiondisclosed herein without departing from the spirit thereof, it isunderstood that all matter herein disclosed is deemed illustrative andnot limiting except as set forth in the appended claims.

Having thus disclosed my invention, I claim as new and desire to protectby Letters Patent:

1. The method of applying high pressure to a body comprising associatingsaid body with a pressure applying means and a quantity of freezableexpansible liquid in pressure transmitting relation to each other,interposing a freezable liquid seal between said pressure applying meansand said liquid, confining said body, pressure applying means, liquidand liquid seal, freezing said liquid m1 and subjecting saidcon'fine'dbody and'liquid'to reduced temperature to freeze said liquid.

2. The method of applying high pressure to a body comprising locatingsaid body within a chamber open at one end thereof, disposing a quantityof expansible,.'freezable liquid within said chamber inpressuretransmitting relation to said body, interposing longitudinally movablepressure applying means between said'bodyand liquid, initially freezinga portion of said liquid in a zone adjacent said pressure applyingmeans, thereafter freezing the remainder of said liquid and subjectingsaid body to pressure developed by the expansion of said liquid and theconsequent longitudinal movement of said pressure applying means.

3. The method of applying high pressure to a body comprising disposingsaid body within the bore of a tubular member, disposing a column offreezable liquid within .said bore, interposing a movable pressureapplying means between said body and liquid within said bore, freezing aportion of said liquid at one end of the column adjacent said pressureapplying means, thereafter progressively freezing the remainder of saidcolumn of freezableliqnid between thesaid one end thereof and the otherend thereof. 4. The method of applying'high pressures to a body toeffect a change of state therein comprising associating said body and aquantity of freezable, expansibleliquid inpressure transmitting relationto each other, interposing a pressure applying means between said bodyand said liquid, confining said body, liquid and pressure transmittingmeans in a chamber having cold conductive walls, subjecting a portion ofsaid chamber to sub-freezing tem peratures to freeze a portion of saidliquid immediately adjacent said pressure transmitting means, andthereafter freezing the remainder of said liquid whereby to exert alongitudinally directed pressure upon said pressure transmitting means.

5 The method of applying predetermined pressures to a body comprisinglongitudinally relating said body with a column of freezable, expansibleliquid, interposing a movable pressure applying means between said bodyand said liquid column, confining said body, liquid column and pressureapplying means, subjecting a portion of said liquid column adjacent saidpressure applying means to a temperature for freezing said liquid columnportion to form a seal, and thereafter lowering the temperature of theremainder of said liquid column to a freezing condition whereby to exertlongitudinally directed pressure relative to said pressure applyingmeans, said last men tioned pressure being substantially inverselyrelated to said predetermined pressures.

6. The method of applying pressure to a -body comprising providing anelongated confining chamber, disposing a column of freezable, expansibleliquid'within said chamber, locating saidbody within said chamber in1ongitudinal relation to said liquid column, disposing pressure applyingmeans betweensaid liquid column and 'said body, subjecting a limitedzone of said chamber to temperatures for freezing a portion of saidliquid column adjacent said pressure applying means, and thereaftersubjecting the remainder of said chamber to temperatures for freezingthe remainder of said liquid column.

References Cited in'the file of this patent UNITED STATES PATENTS

